Cannula for receiving surgical instruments

ABSTRACT

A cannula ( 10 ) for receiving surgical instruments for performing a surgical procedure on a body includes a tubular structure ( 12 ) defining a passage ( 16 ) through which the surgical instruments are inserted into the body. The tubular structure ( 12 ) includes an expandable portion ( 40 ) for enabling an increase in the cross-sectional area of the passage ( 16 ). The expandable portion ( 40 ) of the tubular structure ( 12 ) has a slot ( 100 ) and a guide member ( 114 ) disposed in the slot. The guide member ( 114 ) is movable from a first end ( 102 ) of the slot ( 100 ) toward a second end ( 104 ) of the slot to enable the cross-sectional area of the passage ( 16 ) to increase. The expandable portion ( 40 ) has a stop ( 106 ) between the first and second ends ( 102  and  104 ) of the slot ( 100 ) engageable with the guide member ( 114 ) to retain the guide member in a position relative to the slot and resist movement of the guide member from the position relative to the slot.

RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.10/361,887, filed Feb. 10, 2003 now U.S. Pat. No. 7,144,393, which is acontinuation-in-part of U.S. application Ser. No. 09/855,358, filed May15, 2001, now U.S. Pat. No. 6,524,320.

FIELD OF THE INVENTION

The present invention relates to a cannula for receiving surgicalinstruments for performing a surgical procedure on a body.

BACKGROUND OF THE INVENTION

A known cannula for receiving surgical instruments is disclosed in U.S.Pat. No. 6,187,000. U.S. Pat. No. 6,187,000 discloses a cannula havingan expandable portion. The expandable portion has a slot and a guidemember disposed in the slot. The guide member is movable from a firstterminal end of the slot to a second terminal end of the slot to enablethe cross-sectional area of a passage in the cannula to increase.

SUMMARY OF THE INVENTION

The present invention is a cannula for receiving surgical instrumentsfor performing a surgical procedure on a body. The cannula includes atube structure defining a passage through which the surgical instrumentsare inserted into the body. The tube structure includes an expandableportion for enabling an increase in the cross-sectional area of thepassage.

The expandable portion of the tube structure has a slot and a guidemember disposed in the slot. The guide member is movable from a firstend of the slot toward a second end of the slot to enable thecross-sectional area of the passage to increase. The expandable portionhas a stop between the first and second ends of the slot engageable withthe guide member. The stop retains the guide member in a positionrelative to the slot and resists movement of the guide member relativeto the slot from the position.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other features of the present invention will becomeapparent to one skilled in the art to which the present inventionrelates upon consideration of the following description of the inventionwith reference to the accompanying drawings, wherein:

FIG. 1 is an exploded perspective view of a surgical cannula constructedin accordance with a first embodiment of the present invention, thecannula being shown in an expanded condition;

FIG. 2 is a perspective view of the cannula of FIG. 1, the cannula beingshown in a contracted condition;

FIG. 3 is a rollout view of an arcuate segment of the cannula of FIG. 1;

FIG. 4 is an enlarged view of a slot in the arcuate segment of FIG. 3;

FIG. 5 is a schematic end view showing the cannula of FIG. 1 in theexpanded condition;

FIG. 6 is a schematic sectional view of the cannula of FIG. 1 adjacent avertebra of a patient's spine during a surgical procedure;

FIG. 7 is a schematic perspective view of a surgical cannula constructedin accordance with a second embodiment of the present invention, thecannula being shown in an expanded condition;

FIG. 8 is a rollout view of an arcuate segment of the cannula of FIG. 7;

FIG. 9 is a schematic perspective view of a surgical cannula constructedin accordance with a third embodiment of the present invention, thecannula being shown in an expanded condition;

FIG. 10 is a rollout view of an arcuate segment of the cannula of FIG.9;

FIG. 11 is a schematic perspective view of a surgical cannulaconstructed in accordance with a fourth embodiment of the presentinvention, the cannula being shown in an expanded condition;

FIG. 12 is an enlarged rollout view of an arcuate segment of the cannulaof FIG. 11; and

FIG. 13 is a schematic sectional view of a surgical cannula constructedin accordance with a fifth embodiment of the present invention.

DESCRIPTION OF THE INVENTION

The present invention is directed to a cannula for receiving surgicalinstruments during a surgical procedure. The present invention isapplicable to a variety of surgical procedures in which endoscopicsurgical techniques are used.

FIG. 1 illustrates a cannula 10 constructed according to a firstembodiment of the present invention. The cannula 10 is a tubularstructure 12 centered on an axis 14. The tubular structure 12 defines apassage 16 through the cannula 10. Surgical instruments are insertedinto the body during endoscopic surgery through the passage 16.

The tubular structure 12 comprises a first tubular portion 20 and asecond tubular portion 40 attached to the first tubular portion. Thefirst tubular portion 20 is preferably made of a length of stainlesssteel tubing, but could alternatively be made of another suitablematerial, such as a radiolucent material. The first tubular portion 20has a proximal end 22 and a distal end 24. Parallel cylindrical innerand outer surfaces 26 and 28 extend between the ends 22, 24 of the firsttubular portion 20. The first tubular portion 20 has a thicknessmeasured perpendicular to the surfaces 26 and 28 in the range of 0.02inches to 0.04 inches or approximately 0.5 mm to approximately 1.0 mm.

The inner surface 26 (FIG. 1) defines a first passage portion 30 of thepassage 16 through the cannula 10. The first passage portion 30 has adiameter D1 which is preferably in the range from 10 mm to 20 mm orapproximately 0.4 inches to approximately 0.8 inches. The inner surface26 may have a non-reflective coating to reduce glare on any video imageproduced by a video camera inserted through the passage 16.

The second tubular portion 40 of the tubular structure 12 is attached tothe distal end 24 of the first tubular portion 20. The second tubularportion 40 is preferably made from stainless steel, but couldalternatively be made from another suitable material, such as aradiolucent material.

As best seen in the rollout view of FIG. 3, the second tubular portion40 includes an arcuate segment 42 of sheet stock. The arcuate segment 42includes first and second edges 44 and 46. The arcuate segment 42 alsoincludes first and second planar edges 48 and 50 extending between theedges 44 and 46. The first and second planar edges 48 and 50 are rolledin an overlapping manner to form the tubular configuration of the secondtubular portion 40.

When the second tubular portion 40 (FIG. 1) has been rolled into itstubular configuration, the first and second edges 44 and 46 defineoppositely disposed first and second ends 60 and 62 of the secondtubular portion. The first and second ends 60 and 62 are connected by acentral portion 64. The first end 60 of the second tubular portion 40 isattached to the distal end 24 of the first tubular portion 20 by asuitable fastener, such as a rivet 66. It is contemplated that a screwcould be used instead of the rivet 66. The rivet 66 extends through twoaligned apertures 68 at the first end 60 of the second tubular portion40.

The rivet 66 has a first portion 70 and a second portion 72. The firstportion 70 has a shaft 74 extending from a head 76. The shaft 74 extendsthrough the apertures 68 in the tubular portion 40 and the head 76engages the inner surface 26 of the first tubular portion 20. Acylindrical opening 78 extends through the shaft 74 and the head 76.

The second portion 72 of the rivet 66 has a shaft 80 extending from ahead 82. The shaft 80 extends into the opening 78 in the first portion68 of the rivet 66 and the head 82 engages the second tubular portion40. The shaft 80 of the second portion 72 extends into the opening 78 inthe first portion 70 to connect the first and second portions of therivet 66 and pivotally connect the second tubular portion 40 to thefirst tubular portion 20.

The second tubular portion 40 (FIG. 1) includes parallel inner and outersurfaces 90 and 92 extending between the first and second ends 60 and62. The inner surface 90 defines a second passage portion 94 of thepassage 16 through the cannula 10 which extends as a continuation of thefirst passage portion 30 in the first tubular portion 20. The secondtubular portion 40 has a thickness measured perpendicular to thesurfaces 90 and 92 in the range of 0.003 inches to 0.005 inches orapproximately 0.075 mm to approximately 0.125 mm. The inner surface mayhave a non-reflective coating that reduces glare on any video imageproduced by a camera inserted through the passage 16.

An arcuate slot 100 (FIGS. 1 and 3) is formed in the second tubularportion 40 and extends between the inner and outer surfaces 90 and 92 ofthe second tubular portion. The arcuate slot 100 extends in a directionalong a curvilinear path in the central portion 64 of the second tubularportion 40 toward the end 62 of the second tubular portion. The arcuateslot 100 has a first end 102 located in the central portion 64 of thesecond tubular portion 40. A second end 104 of the arcuate slot 100 islocated adjacent the intersection of the second edge 46 and the planaredge 48 of the arcuate segment 42.

The arcuate slot 100 (FIGS. 3 and 4) has three notches or stops 106between the ends 102 and 104. The notches 106 define three expandedconditions of the second tubular portion 40. The notches 106 extend indirections transverse to the arcuate direction in which the slot 100extends. Although the present invention shows three stops 106, it iscontemplated that the slot could have any number of stops.

A guide member or rivet 114 (FIGS. 1 and 3) is attached to the innersurface 90 of the second tubular portion 40 adjacent the intersection ofthe second edge 46 and the planar edge 50. It is contemplated that aguide pin or screw could be used instead of the rivet 114. In thetubular configuration of the second tubular portion 40, the guide member114 is located in the arcuate slot 100 and is movable along thecurvilinear path of the arcuate slot.

The rivet 114 (FIG. 1) is generally similar to the rivet 66 and,therefore, will not be described in detail. The rivet 114 has a firstportion 116 and a second portion 118. The first portion 116 has a shaft120 extending from a head 122. The shaft 120 extends through the slot100 and the head 122 engages a washer 124. A cylindrical opening 126extends through the shaft 120 and the head 122.

The second portion 118 of the rivet 114 has a shaft 128 extending from ahead 130. The shaft 128 extends into the opening 126 in the firstportion 116 of the rivet 114 and the head 130 engages the outer surface92 of the second tubular portion 40. The shaft 120 extends into theopening 126 to connect the first portion 116 of the rivet 114 to thesecond portion 118.

The second tubular portion 40 of the tubular structure 12 is expandablefrom a contracted condition, shown in FIG. 2, to any one of threeexpanded conditions, one of which is shown in FIG. 1. In the contractedcondition, the guide member 114 is located in the first end 102 of thearcuate slot 100 in the second tubular portion 40. The second passageportion 94 defined by the second tubular portion 40 is cylindrical inshape. The second passage portion 94 has a generally constant diameterD2 which is approximately equal to the diameter D1 of the first tubularportion 20. Thus, the cross-sectional area of the second passage portion94 at the second end 62 of the second tubular portion 40 isapproximately the same as the cross-sectional area at the first end 60of the second tubular portion and is approximately the same as thecross-sectional area of the first passage portion 30 in the firsttubular portion 20.

In the expanded conditions (FIG. 1), the guide member 114 engages one ofthe stops 106 and is located in one of the notches 106 in the arcuateslot 100 in the second tubular portion 40. It is also contemplated thatthe guide member 114 could engage one of the stops 106 and be locatedbetween adjacent notches 106. The stops 106 retain the guide member 114in one of a plurality of positions relative to the slot 100 and resistmovement of the guide member from one of the plurality of positionsrelative to the slot. Accordingly, the stops 106 resist contraction ofthe second tubular portion 40.

The second tubular portion 40 has a conical configuration when in theexpanded conditions. At the second end 62 (FIG. 5) of the second tubularportion 40, the second passage portion 94 has a diameter D3 which islarger than the diameter D2 of the second passage portion at the firstend 60. Thus, in the expanded conditions, the cross-sectional area ofthe second passage portion 94 at the second end 62 of the second tubularportion 40 is greater than the cross-sectional area of the secondpassage portion at the first end 60 of the second tubular portion.

The cannula 10 (FIGS. 1 and 2) may include an outer member (not shown)for maintaining the second tubular portion 40 of the cannula in thecontracted condition. It is contemplated that other suitable means formaintaining the second tubular portion 40 in the contracted conditioncould be employed. The outer member may be a layer of plastic tubingwhich is heat shrunk over both the first and second tubular portions 20and 40 to hold the second tubular portion in the contracted condition.In addition, a loop of nylon string (not shown) for tearing the heatshrink tubing is wrapped around the heat shrink tubing so that itextends both underneath and on top of the tubing. An outer end of thestring extends beyond the tubing.

During an endoscopic surgical procedure, the cannula 10 (FIG. 6) isinserted through an incision into a body 138 of a patient in thecontracted condition. The second tubular portion 40 is inserted insidethe body 138. The first tubular portion 20 is inserted into the incisionso that the first tubular portion extends from an exterior of the body138 to inside the body.

The outer end of the string is then manually pulled on by the surgeon.Pulling on the string tears the heat shrink tubing. The heat shrinktubing remains on the cannula 10. With the heat shrink tubing torn, thesecond tubular portion 40 of the cannula 10 is thereby released forexpansion toward one of the expanded conditions.

Next, an expansion tool (not shown) is inserted into the passage 16 inthe cannula 10. The expansion tool is manually operated, causing aradially outwardly directed force to be exerted on the inner surface 90of the second tubular portion 40 by the tool. The second tubular portion40 expands toward one of the expanded conditions. Under the force of theexpansion tool, the guide member 114 slides from the first end 102 ofthe arcuate slot 100 toward the second end 102 of the arcuate slot topermit the expansion of the second tubular portion 40. The guide member114 engages a first stop 106 to position the guide member relative tothe slot 100. If the second tubular portion 40 needs to be expandedfurther, additional force is applied to the second tubular portion tomove the guide member 114. Expansion of the second tubular portion 40can be stopped when the guide member 114 engages one of the stops 106.The guide member 114 engages the stops 106 to position the guide memberin any one of the plurality of positions relative to the slot 100. Thestops 106 resist movement of the guide member 114 relative to the slot100. Accordingly, the second tubular portion 40 has a plurality ofexpanded conditions. The expansion tool is then removed so that one ormore surgical instruments (indicated schematically at 140 in FIG. 6) canbe received through the cannula 10 and inserted into a patient's body138.

The expandable second tubular portion 40 of the cannula 10 provides alarge working area for the surgeon inside the body 140 within theconfines of the cannula. Furthermore, the second tubular portion 40provides a working area that is only as large as needed. As a result,the simultaneous use of a number of endoscopic surgical instruments,including but not limited to steerable instruments, shavers, dissectors,scissors, forceps, retractors, dilators, and video cameras, is madepossible by the expandable cannula 10.

A cannula 210 constructed according to a second embodiment of thepresent invention is illustrated in FIGS. 7-8. The cannula 210 includesa tubular structure 212. The tubular structure 212 defines a passage 216through the cannula 210. Surgical instruments are inserted into the bodyduring endoscopic surgery through the passage 216.

The tubular structure 212 comprises a first tubular portion 220 and asecond tubular portion 240 attached to the first tubular portion. Thefirst tubular portion 220 is identical to the first tubular portion 20described in connection with the embodiment disclosed in FIGS. 1-6.Accordingly, the first tubular portion 220 will not be described indetail.

The second tubular portion 240 of the tubular structure 212 is attachedto a distal end 224 of the first tubular portion 220. As best seen inthe rollout view of FIG. 8, the second tubular portion 240 includes anarcuate segment 242 of sheet stock. The arcuate segment 242 includesfirst and second edges 244 and 246. The arcuate segment 242 alsoincludes first and second planar edges 248 and 250 extending between theedges 244 and 246. The first and second planar edges 248 and 250 arerolled in an overlapping manner to form the tubular configuration of thesecond tubular portion 240.

When the second tubular portion 240 has been rolled into its tubularconfiguration, the first and second arcuate edges 244 and 246 defineoppositely disposed first and second ends 260 and 262 (FIG. 7) of thesecond tubular portion. The first and second ends 260 and 262 areconnected by a central portion 264. The first end 260 of the secondtubular portion 240 is attached to the distal end 224 of the firsttubular portion 220 by a suitable fastener, such as a rivet 266. Therivet 266 extends through two aligned apertures 268 (FIG. 8) at thefirst end 260 of the second tubular portion 240. The rivet 266 isidentical to the rivet 66 described in connection with the embodimentillustrated in FIGS. 1-6. Accordingly, the rivet 266 will not bedescribed in detail.

The second tubular portion 240 (FIG. 7) includes parallel inner andouter surfaces 290 and 292 extending between the first and second ends260 and 262. The inner surface 290 defines a second passage portion 294of the passage 216 through the cannula 210 which extends as acontinuation of a first passage portion 230 in the first tubular portion220.

An arcuate slot 270 (FIGS. 7 and 8) is formed in the second tubularportion 240 and extends between the inner and outer surfaces 290 and 292of the second tubular portion. The arcuate slot 270 extends in adirection along a curvilinear path in the central portion 264 of thesecond tubular portion 240 toward the end 262 of the second tubularportion. The arcuate slot 270 has a first end 272 located in the centralportion 264 of the second tubular portion 240. A second end 274 of thearcuate slot 270 is located adjacent the intersection of the second edge246 and the planar edge 248 of the arcuate segment 242.

A guide member or tab 280 extends from the second tubular portion 240 ata location adjacent the intersection of the second edge 246 and theplanar edge 250 of the arcuate segment 242. The tab 280 is formed bybending a cut-out of the arcuate segment 242 to extend through the slot270. In the tubular configuration of the second tubular portion 240, thetab 280 is located in the arcuate slot 270 and is movable along thecurvilinear path of the arcuate slot.

The second tubular portion 240 of the tubular structure 212 isexpandable from a contracted condition to an expanded condition. In thecontracted condition, the guide member 280 is located in the first end272 of the arcuate slot 270 in the second tubular portion 240. Thesecond passage portion 294 defined by the second tubular portion 240 iscylindrical in shape. The second passage portion 294 has a generallyconstant diameter which is approximately equal to the diameter of thefirst tubular portion 220. Thus, the cross-sectional area of the secondpassage portion 294 at the second end 262 of the second tubular portion240 is approximately the same as a cross-sectional area at the first end260 of the second tubular portion and is approximately the same as across-sectional area of the first passage portion 230 in the firsttubular portion 220.

In the expanded condition, the guide member 280 is located in the secondend 274 of the arcuate slot 270 in the second tubular portion 240. Thesecond tubular portion 240 has a conical configuration. At the secondend 262 of the second tubular portion 240, the second passage portion294 has a diameter which is larger than the diameter of the secondpassage portion at the first end 260. Thus, in the expanded condition,the cross-sectional area of the second passage portion 294 at the secondend 262 of the second tubular portion 240 is greater than thecross-sectional area of the second passage portion at the first end 260of the second tubular portion.

During an endoscopic surgical procedure, the cannula 210 is insertedthrough an incision into the body of a patient in the contractedcondition. The second tubular portion 240 is inserted inside the body.The first tubular portion 220 is inserted into the incision so that thefirst tubular portion extends from an exterior of the body to inside thebody.

An expansion tool (not shown) is inserted into the passage 216 in thecannula 210. The expansion tool is manually operated, causing a radiallyoutwardly directed force to be exerted on the inner surface 290 of thesecond tubular portion 240 by the tool. The second tubular portion 240expands toward the expanded condition. Under the force of the expansiontool, the guide member 280 slides from the first end 272 of the arcuateslot 270 to the second end 274 of the arcuate slot to permit theexpansion of the second tubular portion 240. The expansion tool is thenremoved so that one or more surgical instruments can be received throughthe cannula 210 and inserted into a patient's body.

The expandable second tubular portion 240 of the cannula 210 provides alarge working area for the surgeon inside the body within the confinesof the cannula. As a result, simultaneous use of a number of endoscopicsurgical instruments, including but not limited to steerableinstruments, shavers, dissectors, scissors, forceps, retractors,dilators, and video cameras, is made possible by the expandable cannula210.

A cannula 310 constructed according to a third embodiment of the presentinvention is illustrated in FIGS. 9-10. The cannula 310 includes atubular structure 312. The tubular structure 312 defines a passage 316through the cannula 310. Surgical instruments are inserted into the bodyduring endoscopic surgery through the passage 316.

The tubular structure 312 comprises a first tubular portion 320 and asecond tubular portion 340 attached to the first tubular portion. Thefirst tubular portion 320 has a proximal end 322 and a distal end 324.Parallel cylindrical inner and outer surfaces extend between the ends322 and 324 of the first tubular portion 320. The inner surface definesa first passage portion 330 of the passage 316 through the cannula 310.

The second tubular portion 340 of the tubular structure 312 is attachedto the distal end 324 of the first tubular portion 320. As best seen inthe rollout view of FIG. 10, the second tubular portion 340 includes anarcuate segment 342 of sheet stock. The arcuate segment 342 includesfirst and second edges 344 and 346. The arcuate segment 342 alsoincludes first and second planar edges 348 and 350 extending between theedges 344 and 346. The first and second planar edges 348 and 350 arerolled in an overlapping manner to form the tubular configuration of thesecond tubular portion 340.

When the second tubular portion 340 (FIG. 9) has been rolled into itstubular configuration, the first and second arcuate edges 344 and 346define oppositely disposed first and second ends 360 and 362 of thesecond tubular portion. The first and second ends 360 and 362 areconnected by a central portion 364. The first end 360 of the secondtubular portion 340 is attached to the distal end 324 of the firsttubular portion 320 by a suitable fastener, such a rivet 366.

The rivet 366 is identical to the rivet 66 described in connection withthe embodiment illustrated in FIGS. 1-6. Accordingly, the rivet 366 willnot be described in detail. The rivet 366 extends through alignedapertures 368 (FIG. 10) at the first end 360 of the second tubularportion 340.

The first end 360 (FIGS. 9 and 10) of the second tubular portion 340 isalso attached to the distal end 324 of the first tubular portion 320 bya tab 368 extending from the distal end 324 of the first tubular portion320. The tab 368 extends through an opening 370 in the second tubularportion 340 and is bent over to connect the second tubular portion tothe first tubular portion 320. The end of the tab 368 extending throughthe opening 370 may also be spot welded, soldered, or braized to thefirst tubular portion 320.

The second tubular portion 340 includes parallel inner and outersurfaces 390 and 392 extending between the first and second ends 360 and362. The inner surface 390 defines a second passage portion 394 of thepassage 316 through the cannula 310 which extends as a continuation ofthe first passage portion 330 in the first tubular portion 320.

An arcuate slot 372 is formed in the second tubular portion 340 andextends between the inner and outer surfaces 390 and 392 of the secondtubular portion. The arcuate slot 372 extends along a curvilinear pathin the central portion 364 of the second tubular portion 340 toward theend 362 of the second tubular portion. The arcuate slot 372 has a firstend 374 located in the central portion 364 of the second tubular portion340. A second end 376 of the arcuate slot 372 is located adjacent theintersection of the second edge 346 and the planar edge 348 of thearcuate segment 342.

Guide members or tabs 378 and 380 extend from the second tubular portion340 adjacent the intersection of the second edge 346 and the planar edge350 of the arcuate segment 342. The tabs 378 and 380 are formed bybending cut-outs of the arcuate segment 342 to extend through the slot370. In the tubular configuration of the second tubular portion 340, thetabs 378 and 380 are located in the arcuate slot 372 and are movablealong the curvilinear path of the arcuate slot.

The second tubular portion 340 of the tubular structure 312 isexpandable from a contracted condition to an expanded condition. In thecontracted condition, the tabs 378 and 380 are located in the first end374 of the arcuate slot 372 in the second tubular portion 340. Thesecond passage portion 394 defined by the second tubular portion 340 iscylindrical in shape. The second passage 394 has a generally constantdiameter which is approximately equal to the diameter of the firsttubular portion 320. Thus, the cross-sectional area of the secondpassage portion 394 at the second end 362 of the second tubular portion340 is approximately the same as the cross-sectional area at the firstend 360 of the second tubular portion and is approximately the same asthe cross-sectional area of the first passage portion 330 in the firsttubular portion 320.

In the expanded condition, the tabs 378 and 380 are located in thesecond end 376 of the arcuate slot 372 in the second tubular portion340. The second tubular portion 340 has a conical configuration. At thesecond end 362 of the second tubular portion 340, the second passageportion 394 has a diameter which is larger than the diameter of thesecond passage portion at the first end 360. Thus, in the expandedcondition, the cross-sectional area of the second passage portion 394 atthe second end 362 of the second tubular portion 340 is greater than thecross-sectional area of the second passage portion at the first end 360of the second tubular portion.

During an endoscopic surgical procedure, the cannula 310 is insertedthrough an incision into the body of a patient in the contractedcondition. The second tubular portion 340 is inserted inside the body.The first tubular portion 320 is inserted into the incision so that thefirst tubular portion extends from an exterior of the body to inside thebody.

An expansion tool (not shown) is inserted into the passage 316 in thecannula 310. The expansion tool is manually operated, causing a radiallyoutwardly directed force to be exerted on the inner surface 390 of thesecond tubular portion 340 by the tool. The second tubular portion 340expands toward the expanded condition. Under the force of the expansiontool, the tabs 378 and 380 slide from the first end 374 of the arcuateslot 372 to the second end 376 of the arcuate slot to permit theexpansion of the second tubular portion 340.

The expandable second tubular portion 340 of the cannula 310 provides alarge working area for the surgeon inside the body within the confinesof the cannula. As a result, the simultaneous use of a number ofendoscopic surgical instruments is made possible by the expandablecannula 310.

A cannula 410 constructed according to a fourth embodiment of thepresent invention is illustrated in FIGS. 11-12. The cannula 410includes a tubular structure 412. The tubular structure 412 defines apassage 416 through the cannula 410. Surgical instruments are insertedinto the body during endoscopic surgery through the passage 416.

The tubular structure 412 comprises a first tubular portion 420 and asecond tubular portion 440 attached to the first tubular portion. Thefirst tubular portion 420 has a proximal end 422 and a distal end 424.Parallel cylindrical inner and outer surfaces extend between the ends422 and 424 of the first tubular portion 420. The inner surface definesa first passage portion 430 of the passage 416 through the cannula 410.

The second tubular portion 440 of the tubular structure 412 is attachedto the distal end 424 of the first tubular portion 420. The secondtubular portion 440 includes a plurality of arcuate segments 442 ofsheet stock. The present invention has five arcuate segments 442.However, it is contemplated that any number of arcuate segments 442could be used.

The arcuate segments 442 are identical. Accordingly, only one of thearcuate segments 442 will be described in detail. The arcuate segment442 (FIG. 12) includes first and second arcuate edges 444 and 446. Thearcuate segment 442 also includes first and second planar edges 448 and450 extending between the arcuate edges 444 and 446. The planar edges448 and 450 of the arcuate segments 442 overlap each other to form thetubular configuration of the second tubular portion 440.

When the second tubular portion 440 (FIGS. 11-12) is in its tubularconfiguration, the arcuate edges 444 and 446 define oppositely disposedfirst and second ends 460 and 462 of the second tubular portion. Thefirst and second ends 460 and 462 are connected by central portions 464of the arcuate segments 442. The first end 460 of the second tubularportion 440 is attached to the distal end 424 of the first tubularportion 420 by suitable fasteners, such as rivets 466. The rivets 466extend through aligned apertures 468 at the first end 460 of the secondtubular portion 440.

Each of the arcuate segments 442 includes parallel inner and outersurfaces 490 and 492 extending between the first and second ends 460 and462 of the second tubular portion 440. The inner surfaces 490 define asecond passage portion 494 of the passage 416 through the cannula 410which extends as a continuation of the first passage portion 430 in thefirst tubular portion 420.

Arcuate slots 470 are formed in the arcuate segments 442 and extendbetween the inner and outer surfaces 490 and 492 of the second tubularportion 440. The arcuate slots 470 extend along curvilinear paths in thecentral portions 464 of the arcuate segments 442 toward the end 462 ofthe second tubular portion. The arcuate slots 470 have first ends 472located in the central portions 464. Second ends 474 of the arcuateslots 470 are located adjacent the end 462 of the second tubular portion440. Guide members or rivets 478 are attached to the arcuate segments442. The guide members 478 are identical to the guide member 114described in connection with the embodiment illustrated in FIGS. 1-6.Accordingly, the guide members 478 will not be described in detail. Inthe tubular configuration of the second tubular portion 440, the guidemembers 478 are located in the arcuate slots 470 and are movable alongthe curvilinear paths of the arcuate slots.

The second tubular portion 440 of the tubular structure 412 isexpandable from a contracted condition to an expanded condition. In thecontracted condition, the guide members 478 are located in the firstends 472 of the arcuate slots 470 in the second tubular portion 440. Thesecond passage portion 494 defined by the second tubular portion 440 iscylindrical in shape. The second passage 494 has a generally constantdiameter which is approximately equal to the diameter of the firsttubular portion 420. Thus, the cross-sectional area of the secondpassage portion 494 at the second end 462 of the second tubular portion440 is approximately the same as the cross-sectional area at the firstend 460 of the second tubular portion and is approximately the same asthe cross-sectional area of the first passage portion 430 in the firsttubular portion 420.

In the expanded condition, the guide members 478 are located in thesecond ends 474 of the arcuate slots 470 in the second tubular portion440. The second tubular portion 440 has a conical configuration. At thesecond end 462 of the second tubular portion 440, the second passageportion 494 has a diameter which is larger than the diameter of thesecond passage portion at the first end 460. Thus, in the expandedcondition, the cross-sectional area of the second passage portion 494 atthe second end 462 of the second tubular portion 440 is greater than thecross-sectional area of the second passage portion at the first end 460of the second tubular portion.

During an endoscopic surgical procedure, the cannula 410 is insertedthrough an incision into the body of a patient in the contractedcondition. The second tubular portion 440 is inserted inside the body.The first tubular portion 420 is inserted into the incision so that thefirst tubular portion extends from an exterior of the body to inside thebody.

An expansion tool (not shown) is inserted into the passage 416 in thecannula 410. The expansion tool is manually operated, causing a radiallyoutwardly directed force to be exerted on the inner surfaces 490 of thesecond tubular portion 440 by the tool. The second tubular portion 440expands toward the expanded condition. Under the force of the expansiontool, the guide members 478 slide from the first ends 472 of the arcuateslots 470 to the second ends 474 of the arcuate slots to permit theexpansion of the second tubular portion 440.

The expandable second tubular portion 440 of the cannula 410 provides alarge working area for the surgeon inside the body within the confinesof the cannula. As a result, the simultaneous use of a number ofendoscopic surgical instruments is made possible by the expandablecannula 410. Although the slots 470 are shown as not having stops, it iscontemplated that the slots could have stops or notches similar to thestops 106 described in connection with the embodiment illustrated inFIGS. 1-6.

A cannula 510 constructed according to a fifth embodiment of the presentinvention is illustrated in FIG. 13. The cannula 510 includes a tubularstructure 512. The tubular structure 512 defines a passage 516 throughthe cannula 510. Surgical instruments are inserted into the body duringendoscopic surgery through the passage 516.

The tubular structure 512 comprises a first tubular portion 520 and asecond tubular portion 540 attached to the first tubular portion. Thefirst and second tubular portions 520 and 540 are identical to the firstand second tubular portions 20 and 40 described in connection with theembodiment disclosed in FIGS. 1-6. Accordingly, the first and secondtubular portions 520 and 540 will not be described in detail.

The second tubular portion 540 of the tubular structure 512 is attachedto a distal end 524 of the first tubular portion 520. A first end 560 ofthe second tubular portion 540 is attached to the distal end 524 of thefirst tubular portion 520 by a suitable fastener (not shown), such as arivet. The second tubular portion 540 includes parallel inner and outersurfaces 590 and 592 extending between first and second ends 560 and562. The inner surface 590 defines a second passage portion 594 of thepassage 516 through the cannula 510 which extends as a continuation of afirst passage portion 530 in the first tubular portion 520.

The second tubular portion 540 of the tubular structure 512 isexpandable from a contracted condition to an expanded condition. In thecontracted condition, the second passage portion 594 defined by thesecond tubular portion 540 is cylindrical in shape. The second passageportion 594 has a generally constant diameter which is approximatelyequal to the diameter of the first tubular portion 520. Thus, thecross-sectional area of the second passage portion 594 at the second end562 of the second tubular portion 540 is approximately the same as across-sectional area at the first end 560 of the second tubular portionand is approximately the same as a cross-sectional area of the firstpassage portion 530 in the first tubular portion 520.

In the expanded condition, the second tubular portion 540 has a conicalconfiguration. At the second end 562 of the second tubular portion 540,the second passage portion 594 has a diameter which is larger than thediameter of the second passage portion at the first end 560. Thus, inthe expanded condition, the cross-sectional area of the second passageportion 594 at the second end 562 of the second tubular portion 540 isgreater than the cross-sectional area of the second passage portion atthe first end 560 of the second tubular portion.

A second tubular structure 600 extends into the first tubular portion520 of the tubular structure 512. The second tubular portion 600 extendsinto the first passage portion 530. The second tubular structure 600 hasa radially extending flange 602 with openings 604 for receivingendoscopic surgical instruments and/or for application of suction orirrigation fluid. A tube 608 may extend from the flange 602 adjacent oneof the openings 604 for receiving a surgical instrument and/or theapplication of suction or irrigation fluid.

The second tubular structure 600 includes parallel inner and outersurfaces 610 and 612. The inner surface 610 defines a passage 616through the second tubular structure 600. The outer surface 612 and theinner surface 626 of the first tubular portion 520 define an annularpassage 620. The openings 604 in the flange 602 of the second tubularstructure 600 communicate with the annular passage 620. Accordingly,surgical instruments extend through the openings 604 into the annularpassage 620.

During an endoscopic surgical procedure, the cannula 510 is insertedthrough an incision into the body of a patient in the contractedcondition. The second tubular portion 540 is inserted inside the body.The first tubular portion 520 is inserted into the incision so that thefirst tubular portion extends from an exterior of the body to inside thebody.

Next, an expansion tool (not shown) is inserted into the passage 516 inthe cannula 510. The expansion tool is manually operated, causing aradially outwardly directed force to be exerted on the inner surface 590of the second tubular portion 540 by the tool. The second tubularportion 540 expands toward the expanded condition. The expansion tool isthen removed so that the second tubular structure 600 may be insertedinto the passage 516.

The second tubular structure 600 is inserted into the passage 516 todefine the annular passage 620. Surgical instruments can be receivedthrough the openings 604 in the flange 602 and into the annular passage620 and one or more surgical instruments can be received through thepassage 616 and/or suction or irrigation fluid can be applied throughthe passage 616. As a result, the simultaneous use of a number ofendoscopic surgical instruments is made possible by the cannula 510.

From the above description of the invention, those skilled in the artwill perceive improvements, changes and modifications. Suchimprovements, changes and modifications within the skill of the art areintended to be covered by the appended claims.

1. A surgical retractor, comprising: an elongate body comprising a firstcomponent and a second component and a connector that connects the firstcomponent and the second component; wherein the connector comprises aslot in each of the first and second components, and a guide member oneach of the first and second components, each guide member moveable inthe slot of an adjacent component; wherein at least one of the firstcomponent and the second component is moveable along a length of theslot of an adjacent component, and wherein upon said movement theelongate body moves from a first position to a second position andcauses a distance between the first component and the second componentto change; wherein the first component and second component comprise atleast two retractor blades; and further comprising a third component anda fourth component and a second connector that connects the thirdcomponent and the fourth component, wherein at least one of the thirdcomponent and the fourth component is moveable along a length of thesecond connector and causes a distance between the third component andthe fourth component to change, and wherein the first component and thesecond component are in moveable relation to the third component and thefourth component.